I have this weird gooey white growth all over my drooping maple tree on my balcony. I wiped most of it off today as best I could but there's still some left. Anyone know what this is and if it needs to be dealt with?
I don't know, but since no one responded, I am bumping your post.
To me it doesn't look so much like disease as something insectoid - an empty cocoon or shed skin or something. Is that what all the rest of it looked like?
There are various insect pests which could be damaging/weakening your tree. Have you looked closely for bugs? Check the underside of leaves, trunk, branches and the soil around your tree.